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jeremybenn |
/*
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(C) Copyright 2001,2006,
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International Business Machines Corporation,
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Sony Computer Entertainment, Incorporated,
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Toshiba Corporation,
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the names of the copyright holders nor the names of their
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contributors may be used to endorse or promote products derived from this
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software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
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OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _FREXP_H_
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#define _FREXP_H_ 1
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#include <spu_intrinsics.h>
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#include "headers/vec_literal.h"
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/* Return the normalized fraction and exponent to the number x.
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* Double precision denorms treated as zero and return a 0
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* fraction and 0 exponent. The results are undefined for infinities
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* and NaNs (double precision only).
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*/
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static __inline double _frexp(double x, int *pexp)
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{
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vec_int4 exp;
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vec_uint4 denorm, mask;
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vec_double2 in, mant;
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vec_double2 half = VEC_SPLAT_F64(0.5);
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vec_ullong2 exp_mask = VEC_SPLAT_U64(0x7FF0000000000000ULL);
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in = spu_promote(x, 0);
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/* Normalize the mantissa (fraction part).
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*/
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mant = spu_sel(in, half, exp_mask);
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/* Zero the mantissa if the input is a denorm or zero
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*/
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exp = spu_and(spu_rlmask((vec_int4)in, -20), 0x7FF);
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denorm = spu_cmpeq(exp, 0);
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mask = spu_shuffle(denorm, denorm, VEC_SPLAT_U8(0));
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mant = spu_andc(mant, (vec_double2)mask);
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/* Zero exponent if zero or denorm input. Otherwise, compute
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* exponent by removing the bias.
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*/
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exp = spu_andc(spu_add(exp, -1022), (vec_int4)mask);
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*pexp = spu_extract(exp, 0);
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return (spu_extract(mant, 0));
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}
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#endif /* _FREXPF_H_ */
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